Question

A 1.2–liter tank at a temperature of 27°C contains a mixture of 1.5 moles of oxygen, 1.2 moles of nitrogen, and 1.6 moles of hydrogen. What is the total pressure of the mixture inside the tank? (R = 0.08205 L atm/K mol)

Answer 1

You can use PV=nRT to figure this out, solving for P. In this case:

V = 1.2 L
n = 1.5 + 1.2 + 1.6 = 4.3 mol (assuming the question is giving moles of molecular O/N/H)
R = 0.08205 L atm/K mol
T = 27C = 300 K

P = nRT/V = 4.3 * 0.08205 * 300 / 1.2 = 88.2 atm

Answer 2

Correct answer is 88.23 atmospheres.